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05 June 2012

The “white one”: some facts about beluga whales

The beluga whale is known in science as Delphinapterus leucas, meaning the “white one”, alluding to its body color. It is a POLAR species, and calls the ARCTIC Ocean home. It is found in shallow coastal waters, but migrate to deep, offshore waters when the ice freezes over during the winter (Jefferson et al., 1993). It also enters estuaries and rivers during spring and summer to feed and take care of its calf. It feeds on various species of fish like cod and salmon, a wide variety of mollusks and benthic invertebrates like shrimps, crabs and octopuses (Kastelein et al., 1994). As a social animal it is extremely vocal, producing whistles, chirps, clicks and squeals, which gave it the title of “sea canary”, because it has the best singing voice in the whale world (Friedman, 2006). Belugas form pods consisting either of only males, or of only females and their young (IUCN, 2009).

Like most whale species, the beluga is “Near threatened” (IUCN Red List, 2008). The following may explain why this is so:

It is long-lived and slow growing, becoming mature only at 4 to 7 years old and grows to a maximum length of 5.5 m ( Stewart and Stewart., 1989). Like humans, it only conceives one calf at a time and may have 10 to 13 calves through its life-time (Stewart and Stewart., 1989). These two factors limit its capacity to produce young and thus to repopulate.

Calf survival is dependent on environmental conditions, one of the major ones being food source. One of its main fish food, the cod, has almost disappeared from overfishing in one of the beluga’s major spawning grounds in eastern Canada (Myers et al., 1996). Thus, food source is also a limiting factor for population growth.

It accumulates high concentrations of toxins from the food chain and also from water pollution. Some belugas eventually perish due to pollution (IUCN, 2009), again adding to the list of factors limiting its population growth.

As in most whales, noise pollution (like the drumming of a ship motor) disturbs its sonic system. Noise affects the beluga’s capacity to detect other animals and/or structures along its path. This could be the cause of some maritime accidents involving whales and boat propellers, the most common accident being ship strikes (IUCN, 2009). In addition, a whale’s sonic system also orients its migration, for instance, its summer feeding migration (Friedman, 2006). Thus, noise pollution may also cause disorientation and a change in the migration behavior of some whales (IUCN, 2009); the beluga whale being a case in point. This means that a whale’s capacity to feed and fend for its young might be affected if it cannot ‘find its way’ to its summer feeding grounds; which is again, a factor that may cause its demise.

Given the reasons enumerated above, we then wonder what advantages there might be in taking an Arctic animal out of its natural habitat to be kept in a tropical country aquarium? Consider the following:

The tank has to be large enough to hold the whale and make enough room for it to swim around. At the Vancouver (Canada) aquarium, beluga whales are kept in Olympic-size pools maintained by scientific personnel, and yet, captive belugas still perish (Ward and Duggan, 2011);

The tank has to be cooled from 30°C to 0°C in order to emulate Arctic water temperature. This will require a whole lot of energy to maintain, which will increase the electrical consumption for any city hosting this animal for show;

Finally, the beluga is under the protection of CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora). It was placed under Appendix II, which means that the international trade of this species is monitored. Permits for export will only be granted if it will not be detrimental to the survival of the species and was not obtained in contravention of the laws of the state for the protection of Flora and Fauna.

Now, having read the above information, do you still think that there is any advantage to having a beluga show in a tropical country, except for the purpose of pleasing a misinformed (though paying) public?